From practice a swivel chair is known comprising a seating part mounted in a leg by means of a shaft so that the seating part can freely rotate about the shaft. As a result, it is possible to change the position of the seating part relative to the leg. For that purpose, a user of the chair should take off with his or her feet against the floor or another object connected to the fixed world, and, having reached the desired position, stop himself with his feet. In fact, for taking off and/or braking, it is also possible to use one's hands, provided that a grip suitable therefor be present. Such a swivel chair has a simple construction and may be easy to operate. However, this known swivel chair has as a drawback that a stationary point should always be present for taking off. If the feet are used therefor, they should be placed on the floor and hence, during the rotation, they cannot remain positioned on, for instance, a foot rest rotating along. Further, a floor or the like should be present, which is not always the case, for instance when the swivel chair is used with a stair lift. Moreover, the user should have the disposal of at least one foot which, moreover, should be able to produce the necessary power, which will often not or at least not always be the case with, in particular, semi-invalid and elderly users. Comparable drawbacks apply to the use of one's hands for taking off and/or braking.
Further, from practice, swivel chairs are known whose rotation can be initiated and/or braked through electric or like, not strictly mechanical energization. Such a swivel chair is complicated and costly in manufacturing, use and maintenance and is moreover relatively voluminous.
A swivel chair known from U.S. Pat. No. 4,544,202 comprises a seating part and a support part. The seating part is pivotly connected to the support part via a first axis of rotation which, during use extends substantially vertically. Mechanical activating means are provided for swivelling the seating part around the first axis of rotation. During use the activating means contact the seating part and the support part whereby operation of the activating means causes exertion of an activating force relative to the support part for initiating of a swivel movement of the seating part.
In this known swivel chair the support part is provided with a bowl shaped base with a series of regularly spaced holes around its edge, concentric relative to the central axis of rotation of the seating part. Under the seating part a gear wheel is provided, the teeth of which can cooperate with said holes in the base, which gear wheel can be rotated by means of a handle extending at the side of the seating part. By rotation of the gear wheel thus the seating part will be rotated around said axis of rotation, to a desired position. In this known swivel chair the movement of the seating part is continuously guided and controlled by the said handle, whereby the seating part can be rotated over 360.degree. or more.
This known swivel chair has the disadvantage that the full movement of the seating part has to be provided for and continuously controlled by the person sitting on the seating part. Furthermore, no specific end positions are provided in such a known swivel chair.